1. Field of the Invention
The present invention relates to a semiconductor device and a method for manufacturing the semiconductor device. In particular, the present invention relates to a semiconductor device which can transmit and receive information without contact and a method for manufacturing the semiconductor device.
2. Description of the Related Art
In recent years, an individual identification technology utilizing electromagnetic waves for wireless communication has attracted attention. In particular, as a semiconductor device which communicates data by wireless communication, an individual identification technology using a semiconductor device (also referred to as a radio frequency identification (RFID) tag, an integrated circuit (IC) tag, an IC chip, an RF tag, a wireless tag, or an electronic tag) utilizing RFID has attracted attention. The individual identification technology using such a semiconductor device utilizing RFID has been useful for production, management, or the like of individual objects, and application to personal authentication has been promoted.
Such a semiconductor device obtains operating power from an electromagnetic wave received from a reader/writer and exchanges data with the reader/writer. The semiconductor device includes an antenna for transmitting and receiving such an electromagnetic wave and an integrated circuit portion. In general, the antenna and the integrated circuit portion are formed separately and then connected to each other.
In the case where the antenna and the integrated circuit portion are formed separately and connected to each other, it is necessary that the two be electrically connected to each other. Connection between a fine terminal of the integrated circuit portion and the antenna is accompanied by technical difficulty, resulting in reduction of yield. Further, stress is applied to a connection point when the semiconductor device is used, which becomes a cause of disconnection or poor connection. In particular, it is expected that poor connection is problematic in the case of using a flexible semiconductor device.
In order to solve the above-described problem of poor connection between the antenna and the integrated circuit portion, a non-contact IC module is known, in which an antenna (also referred to as an on-chip antenna or an on-chip coil) is formed over an integrated circuit portion (for example, Patent Document 1: Japanese Published Patent Application No. 2000-137779).
However, in the case where an antenna is formed over an integrated circuit portion, it is necessary that a conductive film serving as an antenna be further reduced in line width, shape, or the like as the integrated circuit portion becomes fine. As a result, poor connection between the integrated circuit portion and the conductive film serving as an antenna or increase in contact resistance therebetween may be a concern. Further, in the case where the integrated circuit portion is layered, a problem of poor connection may occur which is caused by increase in depth of an opening through which the integrated circuit portion and the conductive film serving as an antenna are connected to each other.